1. Technical Field
The invention relates to an electromechanical locking device having a cylinder lock with a device for transmitting information signals between the lock and a key, a stator housing with a rotor rotatable in this housing, and a blocking device to prevent rotary movement of the rotor in the stator housing and the key.
2. Description of the Prior Art
The combining is known of cylinder locks with mechanically coded holding devices, and with an electromagnetic blocking device. In this way, the safety of the locking device is increased. Especially in bank and treasury equipment, the electromagnetic blocking device acts directly on the bolt of the lock, while they can usually be actuated by an electric or electronic control arranged independently of the mechanical key. Such systems are expensive and require a relatively great amount of installation space. Devices have also been developed in which the information is placed directly on the mechanical key and corresponding reading devices have been built into the cylinder lock to recognize the information signal. By means of the key, a rotor arranged inside the cylinder lock is rotatable, and the locking bolt is actuated by this rotary movement.
Such a locking device is known from German Disclosure No. 3,205,586. In this locking device, the key bears information in the form of magnetic coding. On the cylinder lock is arranged a corresponding reading device which receives the code pulses given off by the key and forwards them to a recognition device. This electronic recognition device is connected with an electromagnetic actuating device. Through a carrier pin, the electromagnetic actuating device can connect the rotor in rotary connection with the element actuating the bolt. This bolt-actuating element is arranged at right angles to the axis of the lock and projects out of the lock cylinder. To produce the necessary forces and lengths of movement of the carrier pin, stable and relatively strong magnets are necessary, by which the outer dimensions of the cylinder lock are much greater than those of locks normally used. Therefore, it is impossible to install such locking devices in doors or equipment already present, without rebuilding them or making fundamental changes. In this known device, the information signals are transmitted by turning the key. Then, if the information agrees with the pulse sequence already in the lock, the rotor is coupled with the bolt-actuating element. Also, this design does not correspond to the known mechanical cylinder locks often used today, and it cannot be seen how this principle could be transferred to these.
The problems of the electromagnets and actuating pins arranged perpendicular to the axis of the cylinder lock were already recognized earlier, and a different solution is shown by European Published Application No. 110,835. In this cylinder lock, actuated by a turning flat key, there is arranged on the outer jacket an electromagnet with a magnet anchor which runs parallel to the axis of the lock. The magnet anchor is provided, at its free end, with added devices which engage in a slide ring. This slide ring is fastened to an extension at the rear end of the rotor and is rotated with same. The electromagnet can be excited by means of an electric control. The blocking part sitting at the end of the anchor is brought into a position in which the slide ring is released for rotary movement. The solution represented here requires an extension of the cylinder lock in the axial direction which is undesirable in many cases. Moreover, the execution of double cylinder locks, in which two mechanical cylinders are combined with each other in the axial direction, is only possible with considerable expense. The axial dimensions of the lock must be changed from those of the known mechanical locks which, in turn, leads to difficulties in changing locks in existing doors and the like.